Side loading fork unit for lift trucks

ABSTRACT

A side loading fork unit for lift trucks comprises a body and mounted for lateral movement in relation to said body forks and intermediate guides. Displaceably mounted in said body for movement in the same direction as said forks and intermediate guides is a hydraulic cylinder provided with teeth for engagement with a gear wheel rotatable about a stationary axis in said body and this gear wheel is fixedly connected to another gear or chain wheel in engagement with a rack or chain, respectively, provided for in said intermediate guide. Furthermore a cable is affixed to and connects the left ends of said cylinder and said fork and runs over a roller in the right end of said intermediate guide. Another cable is affixed to and connects the right ends of said cylinder and said fork and runs over a roller in the left end of said intermediate guide.

United States Patent 1191 Brynts 5] Nov. 19, 1974 SIDE LOADING FORK UNIT FOR LIFT TRUCKS Primary Examiner-Robert J. Spar Assistant Examiner-Lawrence J. Oresky [75] Inventor. Anders Ivar Bryntse, M olby, Attorney Agent or Firm YOung & Thompson Sweden [73] Assignee: AB BYGG- OCH Transportekonomi j y Sweden [57] ABSTRACT [22] Filed: June 1973 A side loading fork unit for lift trucks comprises a [21] Appl. No.: 373,898 body and mounted for lateral movement in relation to said body forks and intermediate guides. Displaceably 30 F A P D mounted in said body for movement in the same direcorelgn pp canon Horny am tion as said forks and intermediate guides is a hydrau- July 1 l, 1972 Sweden 9i l5/72 cylinder provided teeth for engagement a gear wheel rotatable about a stationary axis in said U-S- Cl- BB, and gear wheel is fixedly connected to an Ilrt. Clother gear or chain wheel in engagement a rack Flald of Search BB, A, or chain respectively provided for in aid intermedi- 214/731, 750 ate guide. Furthermore a cable is affixed to and connects the left ends of said cylinder and said fork and References Clted runs over a roller in the right end of said intermediate UNITED STATES PATENTS guide. Another cable is affixed to and connects the 2,951,599 9/1960 Bogar 2l4/l6.l c right ""1 of Said Cylinder fi for}? and "f Over 3,561,620 2/1971 Willis 214 730 a roller m t l ft end of ald mt rm dmte gulde. 3,598,265 8/l97l Aaronson 214/730 FOREIGN PATENTS OR APPLICATIONS 2 5 Drawmg F'gures l,064,54l 4/1967 Great Britain 2l4/16.l DC

a A k ------F E" "7, H 4 G] ll: [1:1 G 2 5 7 SIDE LOADING FORK UNIT FOR LIFT TRUCKS This invention relates to a side loading fork unit, wherein the forks are mounted for telescopic movement from a center position towards either side. Such units are made to be attached to lift trucks in storage rooms for pallet loaded goods so that the truck can move in as narrow passages as possible.

Such units are known today, but they are generally both complicated and expensive and are mostly used on large, railbound stacking cranes. However, a unit according to the invention can be made so small and simple, that it can be attached also to ordinary lift trucks, thereby enabling the truck passages in storage rooms to be dimensioned only half as wide as is now used when the loading takes place with a truck having the forks extending forward, which truck therefore must have the possibility to turn 90.

In the side loading fork unit according to the present invention there is, as known per se, a body together with forks and intermediate guides displaceably mounted to move to either side in relation to said body, said intermediate guides by their displacement, via chains or cables, affixed at one end to the two ends of the forks, displacing said forks. According to the invention the displacement movement of the forks is stepped up by means of a hydraulic cylinder displaceably mounted in said body, the other ends of said chains or cables being affixed to the two opposite ends of said cylinder, and said cylinder also serves to move the intermediate guides and for that purpose is provided with teeth, which engage a gear wheel rotatable about a stationary axis, said gear wheel being fixedly connected to another gear or chain wheel, which is in engagement with a rack or chain, respectively, in the intermediate guide.

Other objects and advantages of the present invention will become apparent from consideration of the following description taken in connection with the accompanying drawing, wherein:-

FIG. 1 is a front view of the side loading unit according to the invention;

FIG. 2 is a side view of the same unit;

FIG. 3 is a sectional, exploded view of the same unit;

FIG. 4 is a sectional view on an enlarged scale of one of the telescopic forks of the same unit, and

FIG. 5 shows the same unit with the forks extended to the right as far as possible.

In the drawing the unit has a body of beams l with rectangular cross section, into which the forks of a conventional lift truck can be inserted when the unit is attached to such a truck.

U-shaped channels 2 are fastened to these beams 1 and said channels carry rollers 4 on shaft 3. On these rollers 4 there are running guides 5 having grooves 6. Above the guides 5 there are U-shaped forks 7 with shafts 8 and rollers 9, which are running in grooves 10 in the guides 5. To the inside of the U-shaped channels 2 and at their outer ends there are mounted holders for a tubular piston-rod l2 belonging to and passing through a hydraulic cylinder 13 provided with teeth. The cylinder 13 moves along the piston-rod 12 and drives through its teeth a gear wheel 14 rotatable about a stationary shaft 15, mounted in the U-shaped channel 2. Connected to the gear wheel 14 is a larger gear wheel 16, which is in engagement with a rack 17 fastened to the guide 5. To a bracket 18 at each of the cylinder ends is affixed a chain or cable 19,20, which crossing. each other run over rollers 21 rotatably mounted in the opposite ends of the guide 5 and thereafter, again crossing each other are affixed to the opposite ends of the forks 7.

When the unit is provided with more than one fork a synchronizing device is provided for the movement of the guides and thus the forks 7, this device being in the form of a gear wheel 22 for each gear wheel 16 and in engagement with this wheel 16, said gear wheels 22 being firmly connected to each other on a common rotatable shaft 23.

When pressure medium through the piston-rod 12 is supplied for instance to the left end of the cylinder 13, this will be moved to the left and thus force the gear wheels 14 and 16 to rotate clockwise, the gear wheel 16 via the rack 17 thereby moving the guide 5 to the right. The chain 19, which at its one end is affixed to the left end of the cylinder 13 and runs over the roller 21 in the right end of the guide 5 to be affixed at its other end to the left end of the fork 7, will thereby move the fork 7 a distance B (FIG. 5) in relation to the guide 5, said distance being equal to the movement A of the guide 5 plus the movement of the hydraulic cylinder in relation to the body of the unit. The fork 7 can hereby be moved a distance C outside the body of the unit, which distance is necessary to bridge a required clearance between the unit and stock pile and without the need of the guide 5 to leave the center line of the unit. At the same time only a single central driving wheel for the guide 5 is required.

I claim:

1. A side loading fork unit for lift trucks, comprising a body and forks and intermediate guides mounted for lateral movement relative to said body, a hydraulic cylinder mounted for movement on said body in the same direction as said forks and intermediate guides, said cylinder having teeth thereon that engage with a gear wheel mounted on said body for rotation about a stationary axis, said gear wheel being fixedly connected to another gear or chain wheel in engagement with a rack or chain, respectively, on said intermediate guide, and a chain or cable secured to and interconnecting the left ends of said cylinder and fork and extending over a roller on the right end of said intermediate guide and another chain or cable secured to and interconnecting the right ends of said cylinder and fork and extending over a roller on the left end of said intermediate guide.

2. A unit as claimed in claim 1, said another gear or chain wheel having a larger diameter than the firstmentioned gear wheel thereby to multiply the motion between said cylinder and intermediate guides. 

1. A side loading fork unit for lift trucks, comprising a body and forks and intermediate guides mounted for lateral movement relative to said body, a hydraulic cylinder mounted for movement on said body in the same direction as said forks and intermediate guides, said cylinder having teeth thereon that engage with a gear wheel mounted on said body for rotation about a stationary axis, said gear wheel being fixedly connected to another gear or chain wheel in engagement with a rack or chain, respectively, on said intermediate guide, and a chain or cable secured to and interconnecting the left ends of said cylinder and fork and extending over a roller on the right end of said intermediate guide and another chain or cable secured to and interconnecting the right ends of said cylinder and fork and extending over a roller on the left end of said intermediate guide.
 2. A unit as claimed in claim 1, said another gear or chain wheel having a larger diameter than the first-mentioned gear wheel thereby to multiply the motion between said cylinder and intermediate guides. 